SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad14d2d9bcae8ccea2e282c09759ba76c31d97ae6998a5087a6bcddf09aa3bf5' 
  AND token = 'EZOY/FQUF0P7E9KaIkY1xvrP/x+bZjqXPx50vakQI44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}